Means for gas-cleaning



r; THOMSON ET AL MEANS FOR GAS CLEANING Filed July 15, 1928 Patented Dec. 8, 1931 1 9 9 UNITED STATES PATENT OFFICE THOMAS THOMSON AND NICHOLAS NISBET, OF SCUNTHORPE, ENGLAND MEANS roa GAS-CLEANING Application filed July 13, 1928, Serial No. 292,600%, and in Great Britain July 23, 1927.

This invention relates to gas-cleaning, that space 5 with sufiicient velocity to ensure that is to say the removal of suspended matter the dust with which it is laden is not drawn (hereinafter also referred to as dust) from back into and miXed with the cleaned gas. gases containing it. The object of the in- The gas from the outlet 8 may be passed to 5 vention is to provide simple and cheap appaother apparatus for further treatment or may ratus for efiiciently performing the desired be returned to the inlet to the separator 2. o rati n, In the construction shown in Figure 2, the In order that the invention may be readily dirty gas from the inlet 1 passes tangentially understood it will be described with reference into the cylindro-conical separator 2, the 10 to the accompanying diagrammatic drawclean gas being removed through the central ings, in which Figure 1 shows a section of a outlet 9. The dust and dirty gas pass downform of apparatus comprising a centrifugal wardly through the annular outlet 10 between separator and a settling chamber, and Figure the lower edge of the separator 2 and a coni- 2 shows an arrangement comprising a cencal baffle 11, into the secondary separator 6 15 trifugal separator, a settling chamber and a provided with a dust outlet 7 as before. The fan for returning gas cleaned in the settling gas which has been re-c1eaned in separator chamber to the inlet to the centrifugal sepa- 6 passes under the battle and through the outrator. Figure 3 shows a modified form of let duct 12to the fan 13 and back through the 20 the arrangement shown inFigure 2 in which duct 14 to the dlrty gas inlet 1.

the outlet from the centrifugal separator is The arrangement shown in Figure 3 is simarranged downwardly. llar to that shown in Figure 2, save that the In the arrangement shown in Figure 1, clean gas is removed downwards through the dust-laden gas is tangentially admitted central outlet 15, instead of in an upward dis 5 through conduit 1 into the centrifugal separection.

rator 2 which is of cylindrical form. The Wlth the arrangements in which gas from gas is thus caused to perform a whirling mothe secondary separator is returned to the tion about the axis of the separator, the dust centrifugal separator, it should be noted that being thereby thrown to the periphery of the the centrifugal separator 2 should be of sufliseparator 2. The clean gas from the central cient capaclty to deal with the full volume of zone of the chamber is Withdrawn through dirty gas to be treated plus the volume of gas 8 the flared mouth 8 of the conduit 4 (the priwhich is withdrawn from the secondary sepmary outlet) whilst the dust and dirty gas arator and returned to the inlet to the cenat the periphery of the chamber pass downtrlfugal separator. wardly through the annular space 5 between We claim the flared mouth 3 and the wall of the sepa- 1. Gas-cleaning apparatus comprising a 8 rator 2. The flow of the cleaned gas into centrifugal separator having an inlet for gas and through the primary outlet may be mainto be cleaned, an outlet for gas cleaned in the tained by any desired means, preferably those sald separator, a conical baiile member, an anembodied in the plant to which the invennular outlet formed between the wall of the ti i li d said separator and the said conical baflie After passing through the annular space 5 member, separating means connected to the the dust and dirty gas enter the secondary said annular outlet, an outlet for matter sepseparator 6 which is shown as a simple setarated in the said separating means, and an 45 tling chamber provided with a closure 7 Outlet I' g from the said separating through which the dust which collects in the means. separator may from time to time be removed. 2. Gas-cleaning apparatus comprising a An outlet 8 for the re-cleaned gas is provided centrifugal separator having an inlet for gas in the separator 6, which is connected to some to be cleaned, an outlet for gas cleaned in the means such as a fan which ensures that the said separator,'a conical baffle member, an dirty gas flows through the annular outlet annular outlet formed between the wall of the said separator and the said conical baflle member, separating means connected to the said annular outlet, an outlet for matter separated in the said separating means, an outlet for gas from the said separating means, the said latter outlet having its mouth positioned coaxial with and adjacent to the conical ba-flie member aforesaid.

3. Gas-cleaning apparatus comprising a centrifugal separator having an inlet for gas to be cleaned, an outlet for gas cleaned in the separator, a conical baffle member, an annular outlet formed between the Wall of the said separator and the said conical bafile member, a settling chamber connected to the said annular outlet, an outlet for matter separated in the settling chamber, an outlet for gas from the said settling chamber, the said latter outlet having its mouth positioned coaxial with and adjacent to the conical baffle member aforesaid, and means for Withdrawing gas through the said latter outlet and for returning the Withdrawn gas to the inlet to the said centrifugal separator.

4. Gas-cleaning apparatus comprising a centrifugal separator having an inlet for gas to be cleaned, an outlet for gas cleaned in the said separator, an annular outlet of greater area than the inlet formed at the lower edge of said centrifugal separator for the peripheral discharge therefrom of dirty gas and matter removed from gas cleaned in said separator, additional separating means into which the lower end of said separator projects for the delivery thereinto of the dirty gas and matter discharged from the said annular outlet, an outlet for removing matter separated from the gas in the said additional separating means, and an outlet from said additional separating means for discharge of the gas therefrom.

THOMAS THOMSON. NICHOLAS NISBET. 

